When counting sets that work multiple muscles at once, giving them half credit (instead of full or zero) makes predictions about muscle growth and strength more accurate.
Scientific Claim
The use of the 'fractional' quantification method for indirect sets (assigning 0.5 weight) improves the predictive validity of dose-response models for resistance training adaptations compared to other methods.
Original Statement
“Then, weekly set volume/frequency for indirect sets was quantified as 1 for 'total,' 0.5 for 'fractional,' and 0 for 'direct.' The relative evidence for the 'fractional' quantification method was strongest; therefore, this quantification method was used for the primary meta-regression models.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The claim describes a statistical model comparison and selection, which is appropriately stated as an association based on model fit, not causation.
Evidence from Studies
Supporting (1)
The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains.
This study found that counting half-credit for exercises that indirectly work a muscle (like squats for quads) makes it easier to predict how much muscle and strength you’ll gain from your workouts—better than other ways of counting.